Abstract:In the present research, finite element solutions of thermal post-buckling load-bearing strength of functionally graded (FG) sandwich shell structures are reported by adopting a higher-order shear deformation type kinematics. For the numerical calculation, nine nodes are considered for each element. A specialized MATLAB code is developed incorporating the present mathematical model to evaluate the numerical buckling temperature. The Green-Lagrange nonlinear strain is adopted for the formulation of the sandwich… Show more
“…Basing on the CST, strain components of the TSS are expressed aswherein which u,v and w are displacement components in the x,y and z directions, respectively. The Green-Lagrange nonlinear strain gives more accurate predictions and is usually adopted in numerical approaches, for examples in works of Kar and Panda 56 and Sahoo et al 57,58 Owing to less cumbersomeness and acceptable accuracy, von Kármán–Donnell nonlinear strain is widely used in many studies, e.g. works.…”
An analytical investigation on the nonlinear stability of toroidal shell segment (TSS) made of carbon nanotube (CNT)-reinforced composite, surrounded by an elastic medium, exposed to elevated temperature and subjected to uniform torsion is presented in this paper. The properties of constituents are assumed to be temperature dependent and effective properties of composite are determined using an extended rule of mixture. CNTs are embedded into matrix phase according to functionally graded or uniform distributions. Basic equations in terms of deflection and stress function are established within the framework of classical shell theory including geometrical nonlinearity in von Kármán–Donnell sense and interactive pressure from surrounding elastic medium. Two boundary edges of the shell are assumed to be simply supported and tangentially restrained. Multi-term analytical solutions are assumed and Galerkin method is used to derive expressions of buckling load and nonlinear relation between torsional load and deflection. Parametric studies are carried out to analyze the effects of material and geometry properties, in-plane boundary condition, elevated temperature and surrounding elastic medium on the buckling resistance and postbuckling behavior of torsionally loaded TSS. Novel finding of this study is that tangential edge constraints have no and negative effects on critical torsional loads at room and elevated temperatures, respectively, and profoundly beneficial influences on postbuckling load capacity of TSSs.
“…Basing on the CST, strain components of the TSS are expressed aswherein which u,v and w are displacement components in the x,y and z directions, respectively. The Green-Lagrange nonlinear strain gives more accurate predictions and is usually adopted in numerical approaches, for examples in works of Kar and Panda 56 and Sahoo et al 57,58 Owing to less cumbersomeness and acceptable accuracy, von Kármán–Donnell nonlinear strain is widely used in many studies, e.g. works.…”
An analytical investigation on the nonlinear stability of toroidal shell segment (TSS) made of carbon nanotube (CNT)-reinforced composite, surrounded by an elastic medium, exposed to elevated temperature and subjected to uniform torsion is presented in this paper. The properties of constituents are assumed to be temperature dependent and effective properties of composite are determined using an extended rule of mixture. CNTs are embedded into matrix phase according to functionally graded or uniform distributions. Basic equations in terms of deflection and stress function are established within the framework of classical shell theory including geometrical nonlinearity in von Kármán–Donnell sense and interactive pressure from surrounding elastic medium. Two boundary edges of the shell are assumed to be simply supported and tangentially restrained. Multi-term analytical solutions are assumed and Galerkin method is used to derive expressions of buckling load and nonlinear relation between torsional load and deflection. Parametric studies are carried out to analyze the effects of material and geometry properties, in-plane boundary condition, elevated temperature and surrounding elastic medium on the buckling resistance and postbuckling behavior of torsionally loaded TSS. Novel finding of this study is that tangential edge constraints have no and negative effects on critical torsional loads at room and elevated temperatures, respectively, and profoundly beneficial influences on postbuckling load capacity of TSSs.
“…The smoothing of the stress distribution is another of these benefits. Subsequently, several studies have been realized to investigate the linear and nonlinear static, buckling and vibration responses of FGM micro/nano-structures due to the increased relevance of the functionally graded materials structural components in the design of engineering structures [1][2][3][4][5][6][7]. Melaibri et al [8] demonstrated the vibrationala frequency behaviour of single walled carbon nanotubes (SWCNTs) shells by employing a modern analytical solution based on the Galerkin approach.…”
The bending response of two-dimensional (2D) functionally graded (FG) nonlocal strain gradient nanobeams is explored analytically in this work. The longitudinal and transverse orientations vary in material gradation and material characteristics. Kinematic relations of nanobeams are proposed according to hybrid hyperbolic-parabolic functions. The virtual work principle obtains the equilibrium equations, which are then solved using Navier's method. The accuracy and dependability of the suggested analytical model are demonstrated by comparing the results to predictions made in the literature. A thorough parametric study also determines how sensitive the material distribution, the nonlocal length-scale parameter, the strain gradient microstructure-scale parameter, and the geometry are to how the bending response and stresses of 2D FG nanobeams. The results obtained provide benchmark results, which can be used in the design of composite structures.
“…In order to study and observe the low velocity impact energy response of sandwich structures used for railways, Sakly et al [31] introduced finite element method (FEM), to simulate ballast impacts, a high-speed and low weight test bench was designed. The graded sandwich shell structure's thermal eigenvalue responses are numerically assessed under varied thermal loadings while considering temperature-dependent characteristics as investigated by Sahoo et al [32]. He et al [33] carried out experimentally and numerically the low velocity effect of carbon fiber face sheets and aluminum alloy cores.…”
The aim of this paper is to present a proposed honeycomb core shape and compare it with a normal hexagonal shape core in a sandwich beam. The sandwich cores are simulated in finite element with different materials; aluminum and epoxy-carbon with six layers are used as face sheet and the results are compared to those obtained theoretically. Simulation of 3-point bending test is performed in commercial software ANSYS to verify the analytical results with the numerical ones. Hence, for simplicity one layer of the skin is used on the equivalent model of sandwich for lesser computational time and more accurate evaluation. Simulation of harmonic analysis of hexagonal core and proposed core shape is carried out in frequency domain to identify the core with less deformation under high frequency and it can withstand harmful effects. The proposed core shape model having the same cell numbers and material as the normal hexagonal model is compared with experimental results; it is observed that the proposed core shape model has good flexural stiffness, resonance, fatigue, and stress resistance at a higher frequency.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.